The instant invention relates to a run-flat, tubeless, pneumatic tire and more particularly to a toroidal, reinforced insert for such a run-flat tire.
Flat tires or tires with minimum inflation have long posed serious problems for drivers of vehicles equipped with pneumatic tires. Flat tires usually require that they be changed before the vehicle can proceed, and such a change requires that there be a spare tire situated somewhere on the vehicle, usually in the trunk of a car. A spare tire consumes valuable storage space, and it has therefore become an objective of the automobile and tire industries to provide a tire which would be able to perform, although at reduced speeds, in a flat condition so that the vehicle may be able to proceed to a service center and obtain permanent repairs or replacement, thereby eliminating the need for a spare tire.
There have been many prior art attempts to provide a run-flat tire utilizing inserts in the cavity created by the tire and wheel rim. However, none of these attempts has met with commercial success. The reasons for the failures of the prior art inserts consist of one or more of the following:
1. The insert has proved too difficult to install.
2. The insert, such as a solid rubber buffer, takes up too much enclosed air space and prevents the iron rim from radiating heat from the enclosed air caused by tire flexing, especially at high speed, and the resulting high temperature of enclosed air melts the rubber and vulcanization of the enclosing tire, causing the enclosing tire to wear out in a few hundred or less miles.
3. The insert, such as a steel buffer, though it would run cool, would be too rigid and would bend permanently and cut through the enclosed tire casing if, for example, it were run over a steel railroad rail.
The instant invention overcomes the aforementioned problems of the prior art by providing a novel insert structure for a pneumatic tire.